
import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;


import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 22479
 * Date: 2022-11-28
 * Time: 18:30
 */
//封装DataSource
public class DBUtil {
    //连接数据库 - 使用单例模式中的懒汉模式设计
    private static volatile DataSource dataSource = null;

    private DBUtil() {

    }


    private static DataSource getDataSource() {
        if(dataSource == null) {
            synchronized (DBUtil.class) {
                if(dataSource == null) {
                    dataSource = new MysqlDataSource();
                    ((MysqlDataSource)dataSource).setUrl("jdbc:mysql://127.0.0.1:3306/java105_myblog_system?characterEncoding=utf8&useSSL=false");
                    ((MysqlDataSource)dataSource).setUser("root");
                    ((MysqlDataSource)dataSource).setPassword("");
                }
            }
        }
        return dataSource;
    }

    //连接数据库
    public static Connection getConnection() throws SQLException {
        return getDataSource().getConnection();
    }

    //关闭资源
    public static void close(Connection connection, PreparedStatement preparedStatement, ResultSet resultSet) {
        if(resultSet != null) {
            try {
                resultSet.close();
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }

        if(preparedStatement != null) {
            try {
                preparedStatement.close();
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }

        if(connection != null) {
            try {
                connection.close();
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }
    }



}
